Substance use disorders are a significant public health problem. There is a need for clinician-scientists to be trained to design and conduct clinical trials that translate the latest findings in basic neurobiology and pharmacology of substance use into clinical practice and the development of new treatments. For over two decades The Division on Substance Use Disorders of the Columbia University Department of Psychiatry and the New York State Psychiatric Institute has provided such training to a large cohort of clinical investigators. The purpose of this renewal application is to continue our postdoctoral program focused on training primarily physicians and psychologists for research careers in substance use disorders. The main objective of this program, now in its 24th year of continuous funding, remains to provide both the research skills and clinical expertise necessary to design and carry out independent translational research on the etiology and treatment of substance use disorders. Most of our trainees are encouraged to submit a K award, and about half of our trainees do so while the remainder continues work in affiliation with academic or research institutions. Both outcomes promote our goal of providing research skills and developing future leaders in clinical and treatment research on substance use and related disorders and academic medicine more broadly. Fellows are offered 2 years of training, while a third year may be offered to fellows making excellent progress but needing more time to develop their K awards or other other research proposals. In this competing application we are requesting 5 additional years of funding for 6 postdoctoral fellows to be enrolled in the program each year. We have developed a successful approach to training that includes: 1) Didactic introduction to clinical research in substance-related and addictive disorders that incorporates a comprehensive overview of the substance abuse field, an introduction and advanced course in statistics, weekly journal clubs and methodology seminars, and a formal course and ongoing instruction on the ethical and appropriate scientific conduct of clinical research; 2) Research apprenticeship where each fellow works as a junior collaborator under the close supervision of a senior investigator who serves as a preceptor and mentor; 3) Clinical experience in the major modalities used to treat substance use disorders; and 4) Development of teaching skills where each fellow is provided opportunities to provide lectures/seminars to medical students, psychiatric and other medical housestaff and at journal clubs and scientific meetings. The traditional foci of training remain clinical trials and human behavioral pharmacology. Further, over the past 5 years we have recruited new faculty in order to expand research opportunities for trainees across the translational spectrum and into new frontiers of treatment development. New directions include animal models to human translational work, development of new technologies for diagnostic and therapeutic purposes, health policy, implementation, and services research, adolescent/young adult substance use and neuroimaging.